Fluid-pressure brake.



No. 802,286. PATENTED OCT. 1'7, 1905. M., W. HIBBARD. FLUID PRESSUREBRAKE.

APPLICATION FILED MAR. 13, 1905.

, Zwan/arf nllllllllll 52% MAURY W. HIBBARI), OF CHICAGO, ILLINOIS.

lFLUIlD-'FFIESSURE BRAKE.

Specification of Letters Patent.

Patented Oct. 17, 1905.

Application filed March 13, 1905. Seriai No. 249,779.

To t/Z 1o/'tom it may concern,.-

Be it known that I, MAURY WV. HIBBARD, a citizen oi' the United States,residing at Hawthorne avenue and Rees street, Chicago, in the county ofCook and State of Illinois, have invented anew and useful Improvement inFluid- Pressure Brakes, ot' which the following is a specification.

My object is to provide certain improvements in the construction of theemergency mechanism of automatic airbrake triple valves; and my presentinvention is in the nature of an improvement upon the construction shownin application, Serial No. 238,463, filed by me December 27, 1904:.

The drawing shows a partly broken vertical central section ot' myimproved valve device.

A is the valve-body, having' the train-pipe port e, auxiliary-reservoirport 7), and brakecylinder port c. In the valve-body is a chamber B,having a bushing d, in which works the emergency-valve piston or movableabutment C. The chamber B is in open communication with the train-pipethrough the port (t, and in said chamber in the position shown is asmall port c, from which extends the auxiliary-reservoir feed-passagej', containing' a non-return valve g and terminating at a chamber 71 inwhich is a downwardly-seating valve c', known as the "feed-valve.Beneath the cap A/, which contains the chamber it, is a space I), fromwhich extends a passage if: to the exhaust-port Z ot' the device. Thespace I) is in a ring portion A2 oiE the shell or body portion of thevalve, formed on its inner side with a spider containing' a hub m. Inthe hub mf is a chamber a, from which a passage p extends through one ofthe spider-arms and the shell to the brake-cylinder port or passage c.Fitting and sliding upon the hub is a preferably sectional spacer ordistance-block g, which may be of the exact construction shown in myaforesaid application. Ooniined between the cap A and ring A2 is aflexible diaphragm fr, and contined between the rings A2 and A3 is atiexible diaphragm s. Confined between the ring A3 and the top of themain body portion A is a flexible diaphragm t. The diaphragms fr s bearagainst opposite sides of the spacer (1, whereby they move togetherundervariations of air-pressure. In the chamber a is a release-valve e.In the upper part of the main body portion is a chamber f2.0,communicating through a passage a' with a chamber y/ in rear of thechamber B. In the chamber w and fastened to the diaphragm t is aservice-valve e', working against a seat over a port 2, whichcommunicates with the brake-cylinder port c through a passage 3. Theauxiliary-reservoir port or passage b communicates with the chamber feo,and extending' from the said passage to the space above the diaphragm ris a reservoir feed-passage 4. Extending from the feedpassage f to theupper side of the diaphragm t is a branch passage 5.

The parts thus far described, embracing the feed, release, and servicefeatures of the valve device, are in all main particulars like thoseshown, described, and claimed in my aforesaid application, and a moredetailed description is thought to be unnecessary in the presentconnection. Their operation, briefly stated, is as follows: Air enteringthe chamber B from the train-pipe passes through the port c, passage f',and branch passage 5 to the space above the diaphragm t, pressing thelatter down and seating' the service-valve e.

`The air also passes through the center oi' the ring ASto the under sideot' the double-diaphragm device, pressing the latter upward to firstunseat the release-valve n and then the feed-valve f/. This permitspressure to iiow from the feed-passage f into the space above thediaphragm fr, thence through the feedpassage 41: to lill the auxiliaryreservoir and chambers 'w y. Then the latter are charged with pressureapproximately equaling that of the train-pipe, the parts will be inbalance, the service-valve remaining closed under the relative suctionaction at the port 2. A service reduction of pressure in the trainpipecauses the same reduction to be felt between the diaphragme s z5',permitting the then superior reservoir-pressure bearing upon thediaphragm fr to lower the double-diaphragm device, which causes the feedand release valves to close, and the reservoir-pressure acting againstthe under surface ol the diaphragm t raises the latter and unscats theservice-valve, whereby pressure will liow to the brake-cylinder to applybrakes. When the auxiliary-reservoir pressure drops nearly to the thenreduced train-pipe pressure, the service-valve will close under thesuction at the port 2. The same operations will take place under'further slight reductions of trainpipe pressure for graduations. Willentrainpipe pressure is raised to release brakes, the pressure entersbetween the diaphragme st to press the service-valve iirmly toits seat,open thc release-valve fr, and then in the 'lur- IOO IIO

ther rise of the double-diaphragm device open the feed-valve Thusexhaust of pressure from the brake-cylinder commences before thefeed-valve z' is opened to replenish the auxiliary reservoir.

Extending' between the chambers B y is a large central opening v/,surrounded by a bushing' 6, forming a seat for a valve-ring 7 on therear side of the emergency-piston C. In the bushing CZ of the chamber B,in the position shown, are ports 8, leading to an emergency-passage 9,terminating in an enlargement or chamber 10. The chamber lO communicateswith the brake-cylinder passage c through a port surrounded by a bushing11, forming a valve-seat. Extending' between the chambers 1/ 10 is aguide-opening y2, surrounded by a bushingl 12, presenting a valve-seatin the chamber y. The stem 13 of the piston C extends through theopening y' and is provided toward its end with a screwthread 14 and inits end with a recess or chamber 15. Screwed upon the end of the stem 13is a cup 16, having a central guideopening 17. Confined between theinner end of the cup 16 and the rear face of the piston C is acylindrical spacer or ring 18, carrying' a seating-ring 19, bearingagainst the end of the cup and pressing' at its forward end against thering' 7 to hold the latter in place. The rings 7 19 are preferably ofrubber or other suitable material, which will conform to the seats 6 12and form air-tight joints.

E is the emergency-valve, having a seatingring 2O fitting the seat 11.The valve is upon a sliding extension 21 of the piston-stem 13. Thisextension comprises a shank which carries the valve E and an enlargedhead portion 22 in the chamber 15 and moving or sliding therein betweenthe stops formed by the base of said chamber and the flanged portion ofthe cup 16, surrounding the guide-opening 17. The rear end face 23 ofthe cup 16 may be concave, as shown, and the rear face 24 of the valve Eabout the stem 21 is convex. /Vhen the parts are in vnormal position, asshown, a space 25 exists between the cup 16 and valve E, and the head orshoulder 22 is separated a short distance from both the stops formed bythe base of the chamber 15 and the inwardprojecting end portion of thecup 16.

During the operations of the valve device for service application ofbrakes and while all the parts are in running position the piston C,emergency-valve E, and attendant parts will occupy the relativepositions shown, the piston being held with desired firmness against theseats 6 12 by the emergency-spring 26 shown. To prevent this spring frombuc kling, I provide therein a loose tube 27. At all times when thetrain-pipe pressure exceeds the pressure in the brake-cylinder the valveE will be held to its seat bythe force of trainpipe pressure exertedagainst the rear side of said valve in the space 25. The piston C fitsloosely the bushing (Z, so that the rear side of the piston around theseat 6 is in restricted communication with the train-pipe air.Reservoir-air pressure is normally exerted against the rear side of thepiston over the annular space bounded at its inner annular edge by theseating projection of the bushing 12 and at its outer annular edge bythe seating projection of the bushing 6. Thus as the area against whichreservoir-pressure exerts itself against the piston is comparativelysmall a comparatively weak and sensitive emergencyspring 26 may beprovided. fjcient to cause the reservoirpressure under emergencyreduction of train-pipe pressure to overcome the resistance of thespring' 26 and move the piston C from the seat 6 until the vshoulder at17 engages the emergency-valve stem. This unseating of the pistonpermits the reservoir-air to bear against the entire area of the rearside of the piston, thereby overcoming the resistance of theemergency-valve against unseating and forcing the piston to the positionwhere its annular seating edge 28 bears against the gasket or seat 29.Then the emergency-valve is thus initially opened, a rush of pressurewill take place from the train-pipe through the ports 8 and passage 9 tothe brake-cylinder to effect serial or quick action emergencyapplication of brakes in the manner well understood. Seating of thepiston against the seat 29 shuts ofll communication between thefeed-passage e and train-pipe and also between the ports 8 andtrain-pipe. so that during emergency application of brakes there can beno retrogression of pressure from the brake-cylinder to the train-pipe.hen train-pipe pressure is raised following emergency action, it will,as soon as it, supplemented by the spring 26, is capable of overcomingthe reservoir and brakecylinder pressures, move the piston in thedirection of seating the einergency-valve. As the piston in its backwardmovement opens the ports 8 a sudden retrogression of pressure will takeplace from the brake-cylinder and reservoir to the trainpipe, therebyproducing, as explained in my aforesaid application` serial releasefollowing emergency action. Willen the auxiliary reservoir and brakecylinder are emptied of pressure, there is of course no pressure behindthe emergency-piston C. Then a car with empty reservoir andbrake-cylinder is coupled to a train, usually the full force oftrain-pipe pressure is suddenly let into the triple valve and must passthrough the small feed-port and feed-valve to charge the auxiliaryreservoir and the chamber behind the emergency-piston. In the meantimepressure passes more quickly into the emergency-passage 9, and where, asin my former construction referred to, this pressure can exert itselfThis area is suf-l IOO IIO

against the emergency-valve-in the direction of unseating it, it is aptto open the valve ISO I have shown my improvements in the form in whichI now prefer to provide them; but it will be obvious that changes may bemade in the matter of details of construction without departing from thespirit of my invention as set forth in the appended claims.

What I claim as new, and desire to secure by Letters Patent, is"- 1. Ina device for actuating air-bral es, the combination with feed, releaseand service mechanisms, of a valve-body having an emergency-port andpassage extending from the train-pipe connection to said port, anemergency-valve-operating movable abutment, and a valve for said portmovably connected with said abutment and independently exposed on oneside to seating pressure from said passage.

2. In a device for actuating air-brakes, a valve-body having anemergency-port and passage extending from the train-pipe connection tosaid port, a movable abutment exposed on one side to train-pipe pressureonly and exposed on its opposite side to reservoir and restrictedtrain-pipe pressures,and a valve for said port movably connected withsaid abutment and independently exposed on one side to seating pressurefrom said passage.

3. In a device for actuating air-brales, the combination with a triple-valve body, of quickaction emergency-valve mechanism physically andoperatively independent of the service valve mechanism and comprising amovable abutment exposed on one side to train-pipe pressure only and onits opposite side to auxiliary-rcservoir and restricted train-pipepressures, and an emergency-valve loosely connected with said abutmentand independently exposed at one side to seating' pressure from thetrain-pipe.

4. In a triple valve for air-brakes, emergency-val vc-operatingmechanism comprising a piston, a piston-stem, a cup on the end of thestem, a spacer around thestem interposed between the piston and cup, andseating-rings at opposite ends of the spacer, in combination with anemergency-valve slidably mounted in the cup.

MAURY W. HIBBARD.

In presence oi"-4 J. I'I. LANDES, E. P. RICH.

